Trees deforestation

Next, when considering the use of renewable resources, one must make note of the competing uses for land and the consequent impact on the environment, such as the competition between food production and industrial use for agricultural land, as exemplified by the growing biofuels industry or the deforestation of land for plantations of palm oil trees. This is a complex area where there is on-going national and international debate and where there are no easy answers. 

To illustrate I return to the example of deforestation (Fig. XI. 1). There are a number of peasant plots around a lake. I shall tell three stories about different choices the peasants could be facing. In the first story, deforestation has occurred and erosion is underway. It can be stopped, however, if new trees are planted. Specifically, erosion can be stopped on an individual plot such as A if and only if trees are planted on that plot and on both the adjoining plots, B and C There are two equilibria. In one, no trees are planted and the land is lost to the lake. No individual peasant can do anything to stop it. In the other, trees are planted on all plots and erosion is halted. Given that others cooperate in reforestation, it is in the interest of each to go along. This equilibrium, although better for all than the first, may not be realized. The peasants may not know that their... 

In comparison, the average tree consumes only 1 ton of COz in a lifetime, and an acre of rainforest consumes about 500 tons yearly. When agribusiness, the ethylene industry, or pulp and paper corporations turn forests or rainforests into farmland, they also destroy an effective consumer of COz. The world s fastest-disappearing forests are in Indonesia, where they are cut down either to make paper pulp or to be replaced by palm oil plantations. Palm oil is mostly used to make biodiesel fuels. Tropical deforestation not only results in COz emissions (20% of the global total), but it also poisons the rivers. 

Forestry Indigenous types, minimal deforestation Gradual disappearance of community and individual forests as a result of indiscriminate cutting to pave way for additional land for cultivation, charcoal burning and even for human settlement Tremendous deforestation due to rapid population increase that required more land and cheaper energy sources Tremendous deforestation with concerted efforts for reforestation /afforestation. Hence the introduction of the Shamba system and environmental day trees are planted on public land and farmers encouraged to plant also on their farms... 

To give an idea of how large a forest would need to be in order to supply such vast quantities of wood, let us assume a yield of 325 cord per acre, which for 515,000 trees would require a forest of 1,590 acres, or just short of 2.5 square miles. To put it more graphically, such a forest would have been 2.5 miles long and 1 mile wide. Is it really conceivable that the witnesses and the local residents could have failed to notice such a large deforested area The site would still be apparent today. 

The severity of a storm s impact on humans is exacerbated by deforestation, which often occurs as a result of population pressure. When trees disappear along coastlines, winds and storm surges can enter land with greater force. Deforestation on the slopes of hills and mountains increases the risk of violent flash floods and landslides caused by the heavy rain associated with tropical cyclones. At the same time, the beneficial effects of the rainfall—replenishment of the water resources— may be negated because of the inability of a deforested ecosystem to absorb and retain water. 

Uhl, C., and J. B. Kauffman. 1990. Deforestation, fire susceptibility and potential tree responses to fire in the eastern Amazon. Ecology 71(2) 437-449. 

A second estimate of tropical deforestation (DeFries et al., 2002) was based on coarse resolution satellite data (8 km), calibrated with high-resolution satellite data to identify percent tree cover and to account for small clearings that would be missed with the coarse resolution data. The results yielded estimates of deforestation that were, on average, 54% lower than those reported by the FAO (Table 11). According to DeFries et al., the estimated net flux of carbon for the 1990s was 0.9 (range 0.5-1.4) PgC yr. ... 

This mechanism generates social change not only in capitalism, but in any society in which economic decisions suffer from lack of coordination. Sartre, for instance, takes erosion as his paradigmatic case of counterfinality each peasant seeks to obtain more land by cutting dow n trees on his plot, but a general deforestation induces erosion, with the... 

The definite amount of greenhouse gases in the atmosphere has yet to be calculated. It depends on population, the per capita consumption of fossil fuel, deforestation, forestation activities and countermeasures that balance the extra carbon dioxide in the air. This could include planting more trees. Another factor is the use of alternative energy and conservation. Trades in fuel carbon will also have an effect. Transfers may occur from coal-rich to coal-poor nations. 

The net increase in dissolved-P release from land due to human activities also includes deforestation (plus concurrent soil loss), sewage, and waste sources (Fig. 4). Deforestation, typically by burning after selective tree harvesting, converts the standing stock of P in plant matter to ash. This P is rapidly leached from the ash and transported as dissolved loads in rivers this transfer can happen on timescales of a year or two (Schlesinger 1997). Furthermore, the lack of rooted stability on the landscape results in... 

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